Solar Heater

ABSTRACT

An air-to-air heat exchanging solar heater consists of at least one panel having a frame surrounding a mounting plate. At least one column of recycled aluminum cans consisting of about 17 cans stacked end to end. Each respective can has its top removed (thus having an open top) and the bottom wall having a plurality of holes, preferably four to eight holes ¾″ in diameter. A baffled air column is therefore defined by the end-to-end stacked cans. A low power fan draws air through the column. Preferably, the at least one panel includes 17 columns of 17 cans and the entire assembly (except for the clear panel) is painted black with a high-temperature paint. The at least one panel includes hardware to create an air passage to an existing heating system and draws fresh air from outside.

PRIORITY CLAIM

The present application claims benefit under 35 USC Section 119(e) of U.S. Provisional Patent Application Ser. No. 61/395,736 filed on 17 May 2010. The present application is based on and claims priority from this application, the disclosure of which is hereby expressly incorporated herein by reference.

BACKGROUND

The present invention relates generally to solar heaters and more specifically to a heat exchange device using an air-to-air circulation system consisting of cans or tubes having diffusers.

The current art is replete with solar heaters that provide complex solutions to an age-old problem—how to convert the energy freely provided by the sun into a useable form. More specifically, the current art teaches solar thermal collectors. Predominantly, the current state of the art teaches utilizing a thermal mass to collect solar radiation and a fluid circulating through the thermal mass to extract heat. One such system, as discussed in US 2009/0293862 published on 3 Dec. 2009 to Bailey, teaches a thermal collection cabinet including a thermal mass comprising a corrugated metallic surface with a black finish with a concrete mass. A heat transfer fluid is channeled through the concrete mass. This reference represents the current state-of-the art teaching in solar thermal collector devices. However, it is not without limitations. For example, Bailey teaches the need for a large thermal mass to collect, store and transfer to a fluid serendipitously routed through the thermal mass in an embedded conduit. This adds cost, weight, complexity, unnecessary components, and is otherwise disadvantageous.

Midgley, in U.S. Pat. No. 4,175,541 issued on 1979 Nov. 27, teaches re-using beverage cans to create a solar heating system. Specifically, Midgley describes a solar heating system comprising an enclosure with the front side angled to catch the sun's rays. The front panel has parallel sheets of a transparent material, such as glass or plastic, which enable the rays to pass, but having an insulating air space between them resist outward transmission of heat. Just behind the transparent panels is a collector panel having a plurality of holes through it receiving a quantity of metallic cylinders, such as beverage cans arranged perpendicular to the top glass. The beverage can top, with its pull-tab removed (leaving a single aperture) extends through the holes and the outer surface of the collector panels as well as the outwardly exposed surfaces of the upstanding cans are painted a dark, heat-absorbing paint, whereby the cans will absorb heat and radiate it directly into a heat storage medium, such as a pile of rocks, disposed in a heat storage chamber at the other side of the collector panel. Openings at the bottom and top of the collector panel enable natural circulation of air from the lower portion of the heat storage chamber through the bottom opening to the front of the collector panel, and then up over the collector panel to enter back into the heat storage chamber at the top. A hot air duct exits from the top of the storage chamber and warm air is drawn through by a fan and projected in the room to be heated. Return air enters each storage chamber at the same level that the heated air exits to that there is no natural circulation when the fan is not in operation. During circulation return air is ducted downward to the bottom of the heat storage chamber where it is exited to be heated again. If desired a water line may also extend across the heat chamber at a slight incline to be heated and circulate naturally. Limitations of Midgely include, again, a required thermal mass to trap solar radiation.

Young, in U.S. Pat. No. 4,094,300 issued on 1978 Jun. 13, teaches a solar collector element consisting of a plurality of juxtaposed metal tubular (beverage can) members. Each beverage can is opened to provide a passageway through the top of each can and the lower portions of the can is removed to provide an open bottom connected in tandem to the top rim of an adjacent can. The solar collector element is disposed at an angle on the roof of an existing building and a pump supplies water to the system of linked cans. As with the other teachings, Young instructs a fluid mass acting as a thermal mass to transfer solar radiation to heat a fluid.

Costard, in U.S. Pat. No. 5,028,469 issued on 1991 Jul. 2, teaches a lightweight honey-comb sandwich structure consisting of two cover plates spaced from each other by a plurality of empty cans arranged side by side and perpendicular to the cover panels.

Other references of the current art teach the use of a thermal mass to extract energy or heat from solar radiation combined with a fluid transfer system. Representatives of such teaching include U.S. Pat. No. 4,287,876 to Jacques issued on 1981 Sep. 8, Wardman in U.S. Pat. No. 4,394,814 issued on 1983 Jul. 26, Medico, Jr. in U.S. Pat. No. 3,898,979 issued on 1975 Aug. 12, and Gererd in U.S. Pat. No. 6,513,518 issued on 2003 Feb. 4, for example. A common drawback of each of these references includes the need for a complicated fluid delivery system, pump, and other mechanical fittings and a large thermal mass, all of which add complexity, cost, and reduce efficiency.

Other current art references, such as U.S. Pat. No. 4,203,428 to Fodor issued on 1980 May 20 and U.S. Pat. No. 3,910,490 to Saypalia, Jr. on 1975 Oct. 7, instruct heating an air space and transferring the heated air space to a large thermal-mass consisting of a large water reservoir with associated pump mechanisms. And, a heat-exchanger of Soleau, Jr. described in U.S. Pat. No. 4,135,490 issued on 1979 Jan. 23.

Yet other teachings in the art include heating an air space by solar radiation. For example, the aforementioned U.S. Pat. No. 4,203,428 to Fodor issued on 1980 May 20 teaches the use of blackened aluminum sheets on opposite sides of a plenum enclosure. The interior of the plenum enclosure is divided into an inlet plenum and an outlet plenum. Air is circulated in the plenum at a high rate to extract heat from the thin aluminum sheets as fast as the sheet gain heat from the sun and the heated air is then passed through a water storage tank.

Wiggins et al. in U.S. Pat. No. 4,379,449 issued on 1983 Apr. 12 describe a solar hot air system consisting of a sheet of plate glass abutted to a similarly shaped metal screen, which is painted with a suitable black paint, and a corrugated aluminum collector—painted black—spaced apart from the screen to provide an air space. Air is circulated by means of a small electric fan.

Yet another air-exchanging solar thermal system, the system of Holley et al. in U.S. Pat. No. 4,287,878 issued on 1981 Sep. 8, instructs a frame holding a plurality of cup-shaped elements arranged perpendicular to an clear top surface. The plurality of cup-shaped solar collectors open toward the front of the solar heater structure positioned adjacent to an insulating material whereby cool air is heated by the collectors.

Despite all the teachings of the current state-of-the art, there remains yet a need for a less-complicated, less-costly, and easy to manufacture and maintain system for exploiting the warming rays of the sun and converting solar thermal energy directly to heat an air space. Specifically, there is a need to transfer warm air to a room of a house, but to do so in a very low-cost manner using recycled material such as aluminum beverage containers. The problem of providing a low-cost but thermally efficient solar heater continues to perplex many inventors and home-owners alike. Therefore, it would be very desirable to provide a low-cost solution to this common problem.

SUMMARY OF THE INVENTION

The present invention overcomes the current state of the art—which is replete with multiple designs for do-it-yourself solar heaters: Many of which do not work efficiently or don't work at all. Despite numerous publications, web-sites, and other claims, there has yet to be a way to produce inexpensive heat while using readily available, low-cost materials.

Therefore, advantages to the present invention include providing a low-cost system for heating wherein the material cost and cost of assembly are far lower than otherwise available and, thus, provide a return on investment measured in dollars saved in heating costs relative to material/assembly costs that is less than one year.

In one preferred embodiment a series of parallel tubes, each tube comprising a plurality of stacked recycled aluminum beverage cans modified by having one end removed, preferably the top end, leaving the bottom portion for receiving at least one hole. The remaining end (either top or bottom) includes at least one small opening, but preferably about three to about eight smaller holes, or slots, or fins, or baffles, or any other known means to enable a restricted air flow through that portion of the tube or can. The cans are painted black and the tubes are placed in a frame, housing, or other type of enclosure, which is painted black to increase the amount of heat gain. In this way, solar radiation slowly heats the air inside the stacked cans and the solar gain is as much as 140-degrees. Air is circulated into and out of the stacked cans by low-power electric fans. The fans draw air from a subterranean location at about a temperature of 60 degrees F. Then, when the air in the stacked cans reaches a minimum of 110 degrees F. a small electric fan turns on to circulate the heated air into a living area of a house, or other structure and the fan can be thermally set to turn on when the air temperature reaches 110 degrees F. It should be noted that the system can work without a fan by convection alone.

The stacks of cans arrange in columns of about 7-foot lengths on a standard 4-foot by 8-foot sheet of plywood or particle-board, with a standard frame surrounding the stacks and covered by a sheet of clear glass or plexi-glass. The cans are arranged with the long axis parallel to the plane defined by the sheet of plexiglass, but can otherwise be arranged vertically, horizontally, or at any angle therebetween. Ideally, the entire panel is placed at a about a 57 degree angle from the ground, but other angles will work—especially depending on the latitude of the installation.

With any solar heater, the proof of a good design is in the amount of heat it produces. The first day of operation in November 2010 in the Midwest, when the outside temperature was about 40-degrees F., the solar heater according to the present invention was blowing at about 140-degree F. air into a house—this represents a change of temperature of 100-degrees. On most typical days in the heating season, the conventional furnace need not operate at all.

Ideally, the solar heater of the present invention will be installed on a south-facing exposure. It can be leaned against the house, or placed on a stand adjacent to the house, or otherwise affixed at an inclined angle so to maximize the front of the panel to the winter sun, and, in fact, will work if lying horizontal or standing vertical.

The present invention can be easily assembled from readily available materials using ordinary tools. Such tools and supplies include a drill (press or hand), drill bit, hole saw, saber saw, circular saw, screwdriver, nut driver and can opener, for example. The required materials of a preferred embodiment include about 289 (17×17 matrix of cans) aluminum cans, either a six-inch or eight-inch duct fan with a 250-500 CFM air flow, framing material including plywood sheets, side boards and the like with fasteners such as deck screws, black grill paint rated at 1200-degrees F., a fan control closed at 110-degrees F. and open at 90-degrees F. (Granger Part No. 3F01-111 or SupCo part number SHF110, for example), a Plexiglas or lexan sheet, fasteners, electrical wire, and duct work adapters and furnace pipe to connect panel to existing in-home heating system. Heated air flow from the solar heater of the present invention can be directed directly into a room or structure without going through an existing heating system. For example, a duct can couple to the heater and direct warm air directly room via a window with insulation barricading unwanted outside air inflow.

DRAWING

FIG. 1 is an offset top view of a solar heater system according to a preferred embodiment of the present invention.

FIG. 2 is an exploded assembly view of some components of the system of FIG. 1.

FIG. 3 is a front view of tube or can component of the system of FIG. 1.

FIG. 4 is a detail front view illustrating the component of FIG. 3 with its top removed.

FIG. 5 is another detail front view of the component of FIG. 3.

FIG. 6 is yet another detail front view of the component of FIG. 3.

FIG. 7 is an offset top view of a plurality of cans arranged to form a single tube with baffles according to a preferred embodiment of the present invention.

FIG. 8 illustrates the system of FIG. 1 in a possible environment of use.

FIG. 9 is a back view of the back panel of the system of FIG. 1.

DESCRIPTION OF THE INVENTION

Possible preferred embodiments will now be described with reference to the drawings and those skilled in the art will understand that alternative configurations and combinations of components may be substituted without subtracting from the invention. Also, in some figures certain components are omitted to more clearly illustrate the invention.

A preferred embodiment of the present invention, as illustrated in FIGS. 1-9, includes a solar heating system 10 consisting of at least one heater panel. The heater panel, for example as in Figure, consists of an enclosed air-space assembly 20. This assembly includes a clear top panel 30 mounted on a frame system 40 that includes at least one vertical sidewall. The clear top panel is optional. It keeps weather out and improves efficiency. Opposite the clear top panel, a back panel cooperates to form an air space there between with the frame system's sidewalls completing the enclosure. The top panel 30 is any clear panel material including plate glass, clear plastic, lexan, plexiglass, and the like. Recycled glass patio doors would work equally well. The frame assembly 40 including the back panel 45 and at least one sidewall 40 is ideally framing wood, although other materials would work equally well including metal, composites, plastics, and the like.

Accordingly, FIG. 1 illustrates the air-to-air solar heater system 10 of the present invention. This system consists of a frame and at least one tubular member supported by the frame. The at least one tubular member comprising a thin-walled metal tube having at least one baffle for reducing airflow through the tube, the tube defining an interior air space, the tubular member having an open first end and an oppositely disposed open second end. In addition, a first inner board disposed on the frame and the first inner board further comprising at least one hole disposed thereon, the hole aligning with the interior air space of the tubular member, the tubular member coupled to the first inner board at the open first end. Also, a second inner board disposed on the frame: The second inner board further comprising at least one hole disposed thereon the hole aligning with the interior air space of the tubular member, the tubular member coupled to the second inner board at the open second end. And, finally, an intake means for directing air to the first open end of the at least one tubular member cooperating with an outflow means for enabling the flow of air out of the second open end of the tubular member.

Preferably the frame creates an enclosed air space. The enclosed airspace assembly comprising a clear top panel 30 supported by at least one vertical sidewall 40 and the vertical sidewall coupled to a (bottom or) back panel 45, the top panel, back panel and at least on vertical sidewall cooperating to enclose a volume of space. Further, the system includes an intake means comprising an intake port disposed on the back panel and an outflow means comprising an outflow opening on the back panel. The intake port is disposed at a first end on the back panel adjacent to a first corner and the outflow opening is disposed at a second end of the back panel diagonally opposite the intake port.

FIG. 2 better illustrates the components of the enclosed air-space assembly 20. These components of a preferred embodiment include a clear top panel 30 supported by at least one vertical sidewall. Ideally, four vertical sidewalls 41 42 43 and 44 arrange in a rectangular position at or near the edge of each respective edge of the bottom panel 45 and coupled together to adjacent sidewalls and to the bottom panel with fasteners as would be well-understood in the art. The sidewalls can be each a 1-inch by 6-inch by 8 foot long board (cut to size to match the dimensions of the back panel.) The back panel 45 is a 4-foot by 8-foot sheet of ½-inch thick plywood or, alternatively, 7/16-inch thick oriented strand board (OSB). Alternatively, almost any sized panel can be used as required by the specific installation. The specific dimensions are not critical. It will be understood that greater or lesser efficiencies may result depending on the size of the panel, the surface area of the cans, the size of the duct work, etc.

In addition to the framing members 40, there is a first inner board 61 and a second inner board 62, each board includes a plurality of linearly aligned through holes. In a preferred embodiment adapted to use standard aluminum beverage cans, there are 17 holes disposed on each inner board. For a standard aluminum can, which typically has an outer diameter of 2 and ⅝-inches, a 2 and ½-inch hole is required to support, but now allow the can to slip through, each column of cans. Of course, the idea is to maximize unrestricted air flow through the inner boards but not allow the tubes or stack of cans to slide through. Thus, if a baffled tube (described below) were used in lieu of cans, the opening on the inner board would be correspondingly adjusted in diameter, as may be appreciated by those of ordinary skill in the art. The inner boards adapt to support each of the plurality of tubes or stacked cans so that the cans or tubes do not touch the top or bottom panels.

FIG. 7 shows a tube 50 according to the principles of the present invention. The tube 50 is approximately 7-feet long—however, this size is dependent upon the length of the enclosed air space assembly 20 (previously described)—and thus, the tube may be longer or shorter as required for the specific installation. The tube has at least one sidewall 54 forming a hollow cylindrical shape with a predominantly hollow interior chamber. This interior chamber is periodically interrupted with at least one, and preferably a plurality of baffles 53 that restrict the airflow through the tube. The tube 50 includes an open first end 51 and an open second end 52. Each respective first and second open ends of the each tube couples to the corresponding first and second inner boards 61 and 52 to create an air passage chamber thought the tube 50 and each respective board.

The tube 50 is one of at least one tubular member. Each tubular member comprises a first column comprising a plurality of cans stacked end to end, each can includes an open end and an oppositely spaced baffled end. The baffled end of the can includes a bottom portion of the can and at least one aperture designed to enable air flow through the bottom portion at a slower rate than air flowing through the open top; and adjacent cans in the plurality of cans are arranged so that an open top of a first can abuts the baffled end of an adjacent can, and the adjacent cans are coupled together whereby air flowing through the column is directed predominantly along the length of the column.

The at least one tubular member further comprises a plurality of columns, each column comprising a corresponding plurality of cans. Each column of cans comprises about seventeen cans and the plurality of columns comprises about seventeen columns.

As FIG. 1 shows, the heater system 10 includes a plurality of tubes, ideally 17 tubes in a 4-foot by 8-foot enclosed air space assembly 20. Each tube is a thin-walled metal cylinder (although other shapes would work to a certain extent). A thin aluminum tube works well as solar radiation reflects off the shiny aluminum interior. To increase solar gain, the exterior of the tube is painted with a dark, high-temperature paint.

FIGS. 3-6 illustrate how a typical aluminum beverage can is modified to serve as a component of the hollow tube 50 just described. To form a hollow tube with baffles according to the present invention using aluminum beverage cans (as FIG. 3 shows), a standard aluminum can 70 having a top 71 (with drinking aperture 73), a vertical side wall 75, and solid bottom 77, first, has its top 71 removed (FIG. 4). A preferred method of removing the entire top is to use a can opener. As FIG. 5 shows, with the top removed the can 70 has a vertical sidewall 75, solid bottom 77 and a hollow interior chamber defined by the sidewall and bottom. Next, as FIG. 6 shows, at least one hole 74 is punched or drilled in the bottom. Ideally at least three holes of about ¾-inch in diameter are placed in the solid bottom 77. In other embodiments up to eight such holes are drilled in the bottom. The point of drilling holes in the bottom instead of removing it completely is twofold: one, the bottom adds rigidity to the can and, two, the idea is to slow the air flow—a completely open bottom would defeat these objectives.

Next, the modified cans are stacked end to end wherein the adjacent can's open top abuts directly against the bottom of its neighboring can. In this manner the cans are stacked together to form a tubular column with periodically interspaced baffles. The cans are coupled together by any known means, preferably glued, but they could be pressed together or otherwise attached including welding. The idea is to create a column for air to slowly flow through when installed in the enclosed assembly 20. If using conventional beverage cans, a stack of about 17 cans provides about 7-feet of tube, which inserts into the enclosure leaving about ½-foot at each end of the enclosure.

So, as can be appreciated, a plurality of these tubes 50, or stacked cans, each tube or can stack has periodically spaced baffles and each tube inserts into the enclosure assembly 20 by means of the two opposing inner boards 61 and 62. The inner boards arrange the tubes and space them so that the tubes do not rest on the bottom panel 45 nor touch the top panel 30. Further, the inner boards create a top and bottom plenum where the air from each tube may intermingle with the air from the other tubes.

The back panel, as FIG. 9 shows, includes an cold air intake hole 47 and a warm air outflow port 46. These openings are placed on opposite ends and diagonally across from each other on the back panel to allow air to flow into the first and second plenums, respectively. However, the holes need only be at opposite ends of the back panel to allow airflow and can be on center, for example. In fact, the intake and outflow holes can easily be located on the front panel, or any of the sidewalls.

FIG. 8 shows a possible environment of use of the system 10 according to the present invention. The solar heater with its enclosed airspace assembly 20 faces the sun. It may be placed vertically or horizontally or any angler there between to maximize solar gain for a particular installation location as would be well-appreciated by those in this art. The warm air outflow 46 is assisted by a low-power motorized fan 82, which connects via duct work from the solar heater panel to an existing duct system (such as furnace system 86) or vents directly into an interior space, as necessitated by the installation. A cold air return duct can be included to draw air from the interior enclosed space, or in more temperate climate, be vented directly to exterior air, or a combination of both.

In this environment the intake means further includes a first duct member for directing intake air into the first end of the at least one tubular member and the outflow means further includes a second duct member for directing outflow air to a remote location. Also, as would be appreciated by those in the art, the system further includes insulation means for reducing heat loss from the system.

Although the invention has been particularly shown and described with reference to certain embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. 

1. An air-to-air solar heater system comprising: a frame; at least one tubular member supported by the frame, the at least one tubular member comprising a thin-walled metal tube having at least one baffle for reducing airflow through the tube, the tube defining an interior air space, the tubular member having an open first end and an oppositely disposed open second end; a first inner board disposed on the frame, the first inner board further comprising at least one hole disposed thereon, the hole aligning with the interior air space of the tubular member, the tubular member coupled to the first inner board at the open first end; a second inner board disposed on the frame, the second inner board further comprising at least one hole disposed thereon the hole aligning with the interior air space of the tubular member, the tubular member coupled to the second inner board at the open second end; and an intake means for directing air to the first open end of the at least one tubular member; and an outflow means for enabling the flow of air out of the second open end of the tubular member.
 2. The system of claim 1 wherein the frame further comprises: an enclosed airspace assembly comprising a clear top panel supported by at least one vertical sidewall, the vertical sidewall coupled to a back panel, the top panel, back panel and at least on vertical sidewall cooperating to enclose a volume of space; the intake means comprises an intake port disposed on the back panel; and the outflow means comprises an outflow opening on the back panel.
 3. The system of claim 2 wherein: the intake port is disposed at a first end on the back panel adjacent to a first corner; the outflow opening is disposed at a second end of the back panel diagonally opposite the intake port.
 4. The system of claim 1 further comprising: the at least one tubular member comprises a first column comprising a plurality of cans stacked end to end, each can includes an open end and an oppositely spaced baffled end.
 5. The system of claim 4 wherein: the baffled end of the can includes a bottom portion of the can and at least one aperture designed to enable air flow through the bottom portion at a slower rate than air flowing through the open top; and adjacent cans in the plurality of cans are arranged so that an open top of a first can abuts the baffled end of an adjacent can, and the adjacent cans are coupled together whereby air flowing through the column is directed predominantly along the length of the column.
 6. The system of claim 5 wherein: the at least one tubular member further comprises a plurality of columns, each column comprising a corresponding plurality of cans.
 7. The system of claim 6 wherein: each column of cans comprises about seventeen cans; and the plurality of columns comprises about seventeen columns.
 8. The system of claim 1 wherein: the intake means further includes a first duct member for directing intake air into the first end of the at least one tubular member; and the outflow means further includes a second duct member for directing outflow air to a remote location.
 9. The system of claim 1 further comprising: insulation means for reducing heat loss from the system. 